Silver solutions

Dear histonetters,
Thanks to the net and John Kiernan I am nolonger as wary as I used to
be when working with Sat. picric acid. I am interested to know how
other netters discard silver,ammonia and sodium hydroxide solutions
e.g. in Gordon and Sweet stain. I neutralize the solution with 1%
sodium chloride and then flush it down the basin with a fair amount
of water. (should I be doing this?) In another lab. they collect
the waste solution in a plastic container and then get a waste
company to collect it. (is this a better alternative? I am
concerned about the explosive properties of this mixture when stored
in large quantities before collection. )
Sharon Marshall
Anatomy & Cell Biology
University of Cape Town
South Africa